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Electrophysiological Foundations of Cardiac Arrhythmias Clinical Electrophysiology Mark E Second Edition Electrophysiological Foundations Andrew L. Wit of Cardiac Arrhythmias Penelope A. Boyden A Bridge Between Basic Mechanisms and Electrophysiological Foundations of Cardiac Arrhythmias Electrophysiological Foundations of Cardiac Clinical Electrophysiology Mark E. Josephson Second Edition Hein J. Wellens Now in an abridged second edition, Electrophysiological Foundations of Cardiac Arrhythmias focuses on teaching the fundamental concepts of cardiac cellular • Boyden Josephson Wellens Wit electrophysiology with an emphasis on the relationship of basic mechanisms to clinical cardiac arrhythmias. Understanding this relationship and the electrophysiological mechanisms underlying arrhythmogenesis will be invaluable Electrophysiological to physicians entering the fields of cardiology and clinical electrophysiology, as well as those scientists and clinicians already working in these areas. These essential concepts of electrophysiology include discussion on action potentials, ion channels and currents, and mechanisms of arrhythmias, and Foundations of provide the working knowledge that will enable the reader to approach a board exam confidently. Additionally, the authors build a base of understanding that will prepare the reader for more advanced texts, such as Josephson’s Clinical Cardiac Electrophysiology: Techniques and Interpretations. Cardiac Arrhythmias About the Authors The authors, Andrew L. Wit, PhD, Penelope A. Boyden, PhD, Mark E. Josephson, A Bridge Between MD, and Hein J. Wellens, MD, PhD, have spent four lifetimes investigating and defining electrophysiological mechanisms of cardiac arrhythmias. But equally important, they have devoted their careers to teaching this subject to students of all levels, from medical Basic Mechanisms and students to more advanced cardiology and clinical electrophysiology fellows. Clinical Electrophysiology ISBN 978-1-942909-42-2 Second Edition 90000> This book includes access to a free digital edition for use by the first buyer. For additional information regarding personal or institutional www.cardiotextpublishing.com use, please visit www.cardiotextpublishing.com. 9 781942 909422 Buy Now! Electrophysiological Foundations of Cardiac Arrhythmias A Bridge Between Basic Mechanisms and Clinical Electrophysiology Second Edition Andrew L. Wit, PhD Penelope A. Boyden, PhD Mark E. Josephson, MD Hein J. Wellens, MD, PhD Second Edition First Edition © 2017 Andrew L. Wit, Hein J. Wellens, Mark E. Josephson Second Edition © 2020 Andrew L. Wit, Penelope A. Boyden, Hein J. Wellens Cardiotext Publishing, LLC 3405 W. 44th Street Minneapolis, Minnesota 55410 USA www.cardiotextpublishing.com Any updates to this book may be found at: www.cardiotextpublishing.com/electrophysiological-foundations-of-cardiac-arrhythmias-2ed Comments, inquiries, and requests for bulk sales can be directed to the publisher at: [email protected]. All rights reserved. No part of this book may be reproduced in any form or by any means without the prior permission of the publisher. All trademarks, service marks, and trade names used herein are the property of their respective owners and are used only to identify the products or services of those owners. This book is intended for educational purposes and to further general scientific and medical knowledge, research, and understanding of the conditions and associated treatments discussed herein. This book is not intended to serve as and should not be relied upon as recommending or promoting any specific diagnosis or method of treatment for a particular condition or a particular patient. It is the reader’s responsibility to determine the proper steps for diagnosis and the proper course of treatment for any condition or patient, including suitable and appropriate tests, medications or medical devices to be used for or in conjunction with any diagnosis or treatment. Due to ongoing research, discoveries, modifications to medicines, equipment and devices, and changes in government regulations, the information contained in this book may not reflect the latest standards, developments, guidelines, regu- lations, products or devices in the field. Readers are responsible for keeping up to date with the latest developments and are urged to review the latest instructions and warnings for any medicine, equipment or medical device. Readers should consult with a specialist or contact the vendor of any medicine or medical device where appropriate. Except for the publisher’s website associated with this work, the publisher is not affiliated with and does not sponsor or endorse any websites, organizations or other sources of information referred to herein. The publisher and the authors specifically disclaim any damage, liability, or loss incurred, directly or indirectly, from the use or application of any of the contents of this book. Unless otherwise stated, all figures and tables in this book are used courtesy of the authors. Library of Congress Control Number: 2020934194 ISBN: 978-1-942909-42-2 eISBN: 978-1-942909-48-4 Printed in Canada Table of Contents About the Authors ix Preface: Why Is Basic Cardiac Electrophysiology Important? xi Introduction: How This Book Is Organized xiii Abbreviations and Ionic Currents Involved in Arrhythmogenesis xv CHAPTER 1: Basic Principles of Normal Automaticity 1 General Principles of Normal Automaticity 2 CHAPTER 2: Sinus Node Normal Automaticity and Automatic Arrhythmias 15 Basic Electrophysiological Mechanisms 15 Examples of Arrhythmias Caused by Alterations in Sinus Node Automaticity 37 CHAPTER 3: Atrial, A-V Junctional, and Ventricular Normal Automaticity and Automatic Arrhythmias 45 SECTION 3A: Atrial Normal Automaticity and Automatic Arrhythmias 45 Basic Electrophysiological Mechanisms 45 Examples of Arrhythmias Caused by Atrial Automaticity 49 SECTION 3B: Atrioventricular (A-V) Junctional Normal Automaticity and Automatic Arrhythmias 59 Basic Electrophysiological Mechanisms 59 Examples of Arrhythmias Caused by Alterations in A-V Junctional Automaticity 66 SECTION 3C: Ventricular Normal Automaticity and Automatic Arrhythmias 79 Basic Electrophysiological Mechanisms 79 Examples of Arrhythmias Caused by Alterations in Ventricular Automaticity 82 CHAPTER 4: Abnormal Automaticity: Basic Principles and Arrhythmias 97 Basic Electrophysiological Mechanisms of Abnormal Automaticity 97 Examples of Arrhythmias Caused by Abnormal Automaticity 107 CHAPTER 5: Basic Principles of Delayed Afterdepolarizations (DADs) and Triggered Action Potentials 113 CHAPTER 6: Delayed Afterdepolarizations: Triggered Arrhythmias 133 SECTION 6A: Atrial Delayed Afterdepolarizations and Triggered Arrhythmias 133 Basic Electrophysiological Mechanisms 133 Examples of Arrhythmias Caused by DAD-Triggered Activity in the Atria 134 SECTION 6B: Atrioventricular (A-V) Junctional Delayed Afterdepolarizations and Triggered Arrhythmias 142 Basic Electrophysiologic Mechanisms 142 Examples of Arrhythmias Caused by DAD-Triggered Activity 142 SECTION 6C: Ventricular Delayed Afterdepolarizations and Triggered Arrhythmias 151 Basic Electrophysiological Mechanisms 151 Examples of Arrhythmias Caused by DAD-Triggered Activity in the Ventricle 151 vii viii ¢ Electrophysiological Foundations of Cardiac Arrhythmias: A Bridge Between Basic Mechanisms and Clinical Electrophysiology, Second Edition CHAPTER 7: Basic Principles of Early Afterdepolarizations and Triggered Action Potentials 167 CHAPTER 8: Early Afterdepolarizations: Triggered Arrhythmias 185 Congenital Long QT (LQT) Syndromes 185 Long QT Caused by Structural Heart Disease and/or Ischemia 190 Acquired Long QT Syndrome 191 CHAPTER 9: Basic Principles of Reentry: Altered Conduction and Reentrant Excitation 197 Overview and General Principles 197 CHAPTER 10: Atrial Reentrant Arrhythmias 243 SECTION 10A: Atrial Tachycardias Caused by Reentry in Macroreentrant Circuits 243 SECTION 10B: Atrial Tachycardia Caused by Reentry in Small (Micro) Reentrant Circuits; Focal Reentrant Tachycardia 261 SECTION 10C: Atrial Fibrillation 265 CHAPTER 11: Atrioventricular (A-V) Junctional Reentrant Arrhythmias 277 Reentrant Excitation in the Normal A-V Junction 277 Reentrant Excitation Utilizing an Accessory A-V Conducting Pathway 289 CHAPTER 12: Ventricular Reentrant Arrhythmias 307 Reentry Associated With Nonischemic Cardiomyopathy 324 Reentry in the Ventricular Conducting System 330 Other Reentrant Arrhythmias 338 Index 343 PREFACE Why Is Basic Cardiac Electrophysiology Important? pproximately 55 years ago, the introduction of pro- cardiac electrophysiology must have a solid basic knowl- grammed electrical stimulation of the heart edge foundation of basic electrophysiology. Atogether with the recording of intracardiac electro- This book is designed to lead the reader through the grams, including that of the bundle of His, opened the door pathway from basic cardiac electrophysiology over the for better understanding of the underlying mechanisms of bridge to clinical cardiac electrophysiology. Basic cellular different types of cardiac arrhythmias. This initial diagnos- electrophysiology of the three main categories of arrhyth- tic phase led to new therapeutic possibilities, such as mogenesis (automaticity, triggered activity, and arrhythmia surgery, better selection of antiarrhythmic reentry—see the Introduction and Table i-1) is described in drugs, antitachycardia pacing, and catheter ablation. In sufficient detail to understand how alterations in cellular those 55 years, the number of cardiologists involved in car- electrophysiology cause an arrhythmia.
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